Interceptive Orthodontics 2 Flashcards
Define interceptive orthodontics.
Any procedure that reduces or eliminates the severity of a developing malocclusion.
What is the sequence of permanent tooth eruption (basic timeline)?
6’s: 6 years
1’s: 7 years
2’s: 8 years
4’s: 10 years
3’s & 5’s: 11–12 years
7’s: 12–13 years
When should a contralateral primary tooth exfoliate in normal development?
Within 6 months of its counterpart.
When should you consider extracting a retained primary tooth?
If the permanent successor is present and partially erupted but deflected by the primary tooth.
What is the primary cause of infra-occlusion?
Ankylosis of the primary tooth—surrounding bone grows but tooth doesn’t erupt.
What diagnostic methods help identify infra-occluded teeth?
Percussion test
Check mobility
Radiographs (PA or OPT)
Radiographic signs of ankylosis?
Absence of periodontal ligament space, unclear lamina dura, and potential root resorption.
Management if the permanent successor is present?
Monitor 6–12 months
Extract if below interproximal contact point
Consider timing with root formation
Maintain space post-extraction
Be especially cautious in the upper arch
Risks of not treating infra-occluded primary teeth?
Ectopic eruption of successor
Tipping of adjacent teeth
Periodontal issues
Extraction becomes more difficult
What are your options if the permanent successor is absent?
Retain primary if in good condition (consider onlay)
Extract if infra-occluded beyond interproximal contact
Maintain or reduce space depending on crowding and malocclusion
Use appliances to either maintain space or close it
What are essential components of an upper removable appliance (URA) space maintainer?
Adams clasps on UR6/UL6
Southend clasp on UR1/UL1
Optional: baseplate extension or wire stop distal to UL4
Describe the normal eruption path of upper canines.
Start high and palatal; migrate buccally and distal to lateral incisor root.
By what age should you palpate for the upper canines?
11
Clinical signs of ectopic canines?
Non-palpable canine
Mobile C’s
Lateral incisor angulation, discoloration, or mobility (root resorption)
Radiographic assessment for ectopic canines?
Use parallax technique with OPT + AOM or 2 PAs.
Indications for interceptive extraction of primary canines?
Age 10–13
Canine distal to lateral incisor midline
<55° angulation to mid-sagittal plane
Sufficient space available
Risks of doing nothing with ectopic canines?
Impaction
Root/internal resorption
Cyst formation
Overeruption of lower canines
Ankylosis
More complex future treatment
Name alternatives if interceptive extraction is not suitable or fails.
Monitor and accept position
Surgical exposure and ortho alignment
Extraction
Autotransplantation
What are potential causes of reverse OJ?
Skeletal (e.g., maxillary hypoplasia)
Dental (e.g., anterior crossbite)
Combination
Why is early referral for Class III advised?
Potential for growth modification (if mild skeletal Class III and patient is young).
What features suggest suitability for growth modification?
Mild Class III
Maxillary retrusion
Anterior shift on closing
Average/lowered lower face height
Age 8–10
Growth modification options?
Protraction headgear ± RME (rapid maxillary expansion)
Reverse twin block / Frankel III
Camouflage with URA
What factors influence post-treatment stability in early Class III?
Overbite depth
Growth pattern
Why treat increased OJ early?
Trauma risk (incompetent lips)
Aesthetics/bullying
Greater challenge if delayed
IOTN grades relevant to Class II OJ?
4a: >6mm
5a: >9mm
How do functional appliances work?
Mandible held forward
Muscle stretch + soft tissue pressure transmits to dentition
70% dental, 30% skeletal effect
Must achieve lip competence
Most commonly missing permanent teeth?
Upper laterals and second premolars.
Clinical signs of hypodontia?
Asymmetry
Missing successor on palpation
Retained primary with no mobility
What should be done upon discovering hypodontia?
Radiograph (likely PA in GDP)
Refer with attached imaging
Early interceptive extraction may be required
What are key interceptive actions for:
Unerupted incisors
Habits
Canines
Reverse OJ
Incisors: remove obstruction, make space, observe
Habits: stop before age 9
Canines: assess at age 11
Reverse OJ: consider growth modification
